A new framework and tool for ecological risk assessment of wave energy converters projects

Marine renewable energy has considerable potential for enhancing the diversity of renewable sources, to reduce our reliance on fossil fuels and combat climate change. While the technological development of wave energy converters is progressing rapidly, their environmental impacts are still largely unknown, which is a barrier that could hinder their deployment. This research contributes to the state-of-the-art by introducing a framework for quantifying and analysing the ecological risks of three technologies (oscillating water columns, oscillating wave surge converters, and wave turbines). Based on a literature review, expert consultation process, and the development of a web tool, the potential pressures and the ecosystem elements that might be affected during the life cycle of a generic wave farm (an array of wave energy converters) are investigated. The main pressures are found to be physical disturbance, physical loss, hydrological change, and noise. The ecosystem elements sustaining the largest number of pressures and, therefore, at higher ecological risk are fish and cephalopods species, and benthic and pelagic habitats. The ecological risk assessment framework is operationalized into a free-access web tool (https://aztidata.es/wec-era/) for the interactive assessment and visualisation of the pressures and ecological risks. The tool is intended to be used by managers, decision makers, scientists or promoters during the Strategic Environmental Assessment and Environmental Impact Assessment of wave energy projects. The novel approach presented in this work is more sophisticated than previous risk assessment matrices, enabling to better capture the complexity of the interactions between a wave farm and the environment.